Copy_Screen_To_Bitmap(CRect rcArea, int nBits) { HDC hScrDC, hMemDC; // 屏幕和内存设备描述表 HBITMAP hBitmap, hOldBitmap; // 位图句柄 int xScrn, yScrn; // 屏幕分辨率 HDC hDC; //设备描述表 int iBits; //当前显示分辨率下每个像 WORD wBitCount; //位图中每个像素所占字节 //定义调色板大小， 位图中像素字节大小 ，位图文件大小 ， 写入文件字节数 DWORD dwPaletteSize=0, dwBmBitsSize; BITMAP Bitmap; //位图属性结构 BITMAPINFOHEADER bi; //位图信息头结构 LPBITMAPINFOHEADER lpbi; //指向位图信息头结构 //定义文件，分配内存句柄，调色板句柄 HANDLE hDib; HPALETTE hPal,hOldPal=NULL; //为屏幕创建设备描述表 hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL); // 获得屏幕分辨率 xScrn = GetDeviceCaps(hScrDC, HORZRES); yScrn = GetDeviceCaps(hScrDC, VERTRES); //确保选定区域是可见的 if (rcArea.left < 0) rcArea.left = 0; if (rcArea.top < 0) rcArea.top = 0; if (rcArea.right > xScrn) rcArea.right = xScrn; if (rcArea.bottom > yScrn) rcArea.bottom = yScrn; //为屏幕设备描述表创建兼容的内存设备描述表 hMemDC = CreateCompatibleDC(hScrDC); // 创建一个与屏幕设备描述表兼容的位图 hBitmap = CreateCompatibleBitmap (hScrDC, rcArea.Width (), rcArea. Height ()); // 把新位图选到内存设备描述表中 hOldBitmap = (HBITMAP) SelectObject(hMemDC, hBitmap); // 把屏幕设备描述表拷贝到内存设备描述表中 BitBlt(hMemDC, 0, 0, rcArea.Width (), rcArea.Height (), hScrDC, rcArea.left, rcArea.top, SRCCOPY); //得到屏幕位图的句柄 hBitmap = (HBITMAP) SelectObject(hMemDC, hOldBitmap); //计算位图每个像素所占字节数 iBits = GetDeviceCaps(hScrDC, BITSPIXEL); iBits = iBits * GetDeviceCaps(hScrDC, PLANES); if (iBits <= 1) wBitCount = 1; else if (iBits <= 4) wBitCount = 4; else if (iBits <= 8) wBitCount = 8; else if (iBits <= 24) wBitCount = 24; if (wBitCount > nBits) wBitCount = nBits; //计算调色板大小 if (wBitCount <= 8) dwPaletteSize = (1 << wBitCount) * sizeof(RGBQUAD); //设置位图信息头结构 GetObject(hBitmap, sizeof(BITMAP), (LPSTR)&Bitmap); bi.biSize = sizeof(BITMAPINFOHEADER); bi.biWidth = Bitmap.bmWidth; bi.biHeight = Bitmap.bmHeight; bi.biPlanes = 1; bi.biBitCount = wBitCount; bi.biCompression = BI_RGB; bi.biSizeImage = 0; bi.biXPelsPerMeter = 0; bi.biYPelsPerMeter = 0; bi.biClrUsed = 0; bi.biClrImportant = 0; dwBmBitsSize = ((Bitmap.bmWidth * wBitCount+31)/32)* 4 *Bitmap.bmHeight ; m_dwBmpInfoSize = dwPaletteSize + sizeof(BITMAPINFOHEADER); m_dwBmpSize = dwBmBitsSize + dwPaletteSize + sizeof(BITMAPINFOHEADER); //为位图内容分配内存 hDib = GlobalAlloc(GHND,m_dwBmpSize); lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib); *lpbi = bi; // 处理调色板 hPal = (HPALETTE) GetStockObject(DEFAULT_PALETTE); if (hPal) { hDC = ::GetDC (NULL); hOldPal = ::SelectPalette(hDC, hPal, FALSE); RealizePalette(hDC); } // 获取该调色板下新的像素值 ::GetDIBits( hDC, hBitmap, 0, (UINT) Bitmap.bmHeight, (LPSTR)lpbi + sizeof(BITMAPINFOHEADER) + dwPaletteSize, //(BITMAPINFOHEADER *)lpbi, (BITMAPINFO *)lpbi, DIB_RGB_COLORS ); //恢复调色板 if (hOldPal) { SelectPalette(hDC, hOldPal, TRUE); RealizePalette(hDC); ::ReleaseDC(NULL, hDC); } m_lpBmpData = (char *)lpbi; //清除 DeleteObject (hBitmap); DeleteDC(hScrDC); DeleteDC(hMemDC); return TRUE; }